Roller bearing nut



Aug. 18, 1953 H. e. HENRY ROLLER BEARING NUT Filed Aug. 5, 1952 INVENTOR. Howard G. Hem/"g BY Azo/"neg Patented Aug. 18, 1953 UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a frictionless roller bearing nut, and more particularly to a frictionless roller bearing nut for use on surface grinders or other machine tools.

The object of the invention is to provide a roller bearing nut for use with the lead screw of a precision tool room surface grinder or other machine tool whereby sliding friction which is developed in an ordinary nut is eliminated or omitted so that the life of the screw and nut will be increased to thereby give the user more tool life and less down time or maintenance cost.

Another object of the invention is to provide a roller bearing nut which is constructed so that extremely accurate adjustments can be made and held over a longer period of time so as to provide the machine tool or instrument with a higher degree of precision, the present invention also enabling heavy objects to be moved with finger tip pressure, and when electric power is being used, less power will be required to thereby result in a saving on operating costs, and whereby less expensive motors will be needed.

Still another object of the invention is to provide a roller bearing nut which includes a housing in which is rotatably mounted a plurality of suitable thread type grooved rollers that may be made of any suitable material such as steel or other hard metal to provide the greatest wear life or smoothness of operation, there being a pad arranged in each end of the housing which acts as an oil sealing means and also acts as a wiper to remove away abrasive or foreign products that will tend to cause a scratched surface.

view of the roller bearing nut;

Figure 3 is a sectional view taken on the line 33 of Figure 2;

Figure 4 is a sectional view taken on the line 4-4 of Figure 1.

Referring in detail to the drawings, the numeral l0 designates a housing, and the housing Cal (Cl. Pl-424.8)

I0 is provided with a plurality of spaced parallel longitudinally extending bores ll, Figure 3. R0- tatably arranged in each of the bores H is a suitable thread type grooved roller [2.

The housing H] is further provided with a longitudinally extending passageway M which is adapted to rotatably receive therein a screw i5 which may be the lead screw of a precision surface grinder or other machine tool. Extending 1 through the housing IB- and communicating with one of the bores II is a port l6, the port 16 including an enlarged portion [1, Figure 3. The port I6 is adapted to receive oil or other suitable lubricant whereby the moving parts will beproperly lubricated.

Arranged on each end of the'housing l0 and detachably connected thereto is a plate l8.' The inner surface of each of the plates i8 is cutaway to define a recess I9, Figure 4, and snugly seated within each of the recesses I9 is a pad 261. Each of the pads 20 is provided with a central opening 2| which registers with an opening 22 'in the plate I8, the openings 2| and 22 adapted to have a projected therethrough the screw 15.

For detachably connecting the plates l8to the housing In, a plurality of suitable securing elements such as screws 23 are provided, the screws 23 extending through the plates l8 and into engagement with the housing 10. The housing Iii may also be provided with a locating pilot 2-4.

It will be seen that the rollers I2 are arranged in meshing engagement with the threads on the exterior of the screw I5.

H From the foregoing'it is apparent that a roller bearing nut has been provided which is friction less and which is especially suitable for use with a. precision tool room surface grinder having a:

lead screw, or other machine tool. The advantage of the roller bearing nut of the present invention is that little or no friction is developed in its use. As the screw [5 is revolved, the three contacting rollers 12 revolve with the screw I5. Thus, sliding friction which is developed in an ordinary nut is omitted. Also, end play is negligible since the rollers can be set metal to metal, whereas the solid nut and screw must have sliding room or the screw could not turn. Also, by

eliminating sliding friction, less energy will be required to operate the instrument, so that much i greater loads can be moved with much less power.

Thus, by eliminating friction there will be increased life of the screw and nut to give the user more tool life and less down time or maintenance cost. Also, setting and maintaining no end play insures that more accurate adjustments can be made and held over a longer period of time, and this results in a higher degree of precision machine tools or instruments. Also, heavy objects can be moved with finger tip pressure. Furthermore, where electric power is being used, less power will be required to thereby provide a saving of operating cost and less expensive motors can be used.

The frictionless roller bearing nut of the present invention utilizes three rollers !2 which rest in the three'bores or pockets H. The pockets I I are bored to a size that will permit the rollers I2 to turn freely and yet not sloppy to permitany misalignment. The nut body or housing to,

housing the rollers !2, is made of a close grain two elements or alloys that will result in the greatest wear life or smoothness of operation.

The members I2 are suitable thread type grooved rollers. An acme type thread may be used because the flat top of this type of thread permits a good bearing surface as the rollers l2 revolve in their respective pockets or bores II'. The tapered sides of this type thread provide. a better gripping action as the screw I5 is revolved the rollers l2 must revolve likewise. The. pitch diameter of the screw member I5 determines the location of the pockets H, and the pitch diameter of each of the rollers l2 must mesh properly to avoid end play and give proper action.

The end plates W are secured by suitable screws 23 to each end of the housing or body In to thereby cover the pockets ll completely and act as end thrust plates for the rollers l2. The rollers l2 are made slightlyshorter' than the housing l6 so that they can turn, andthe end plates I8 may be made of brass or some such, metal to give the maximum wear life and free.- dom'of friction.

Also, the end plates 18 are bored to. clear the outside diameter of the screw i5, and an inner recess !9 is cut into each of the end-plates l3 for holding a' felt washer or pad 26,. The felt washer 20 fits into the screw thread and prevents oil from leaking out. Oil enters the hous,-. ing through the port it and since the nut. is sealed at each end, this nut becomes its own oil reservoir. The" felt washers 20 also act. as, wipers and as the screw i5 is run in and out, these wipers 20 remove any abrasive or foreign'particles that will tend tocause a scratched surface or undue wear. A pilot guide member 24. may be provided on the housing IB- to. help align the unit on its preper center line. However, th e pilot guide member 2-4 is not always necessary as other means of alignment maybe used inlieu thereof. The rollers i2. are equally spaced apart, In some instances, the; end plates [-8. mayhouse ball bearings and such ball hearings will' serve to eliminate the friction caused by the. rollers l2 turning within their pockets and bearing on the thread tops. When ball bearings are used the rollers will have projecting ends which-fit.

inside bores of each bearing so that the rollers 6 will turn-freely on ball bearings and there. will be no contact between the since no contact between rollerwill be necessary. It. is to be noted that.

pocket wall and rollerthe pocket wall and 4 three methods of roll finishes may be used, left hand threads, right hand threads, and plain grooves spaced at intervals and formed to fit the screw being used. The preferable method will be the circular groove style. The bores in which the rollers are seated are smooth at all times, and when no bearings are used at each end of each roller, the bore surfaces act as a locater to position each screw and also the bore surfaces will b'ethe sliding bearing-"tor the rollers: Vilhen' bearings areused on each end of each roller the bearing pocket will position each screw and the bore between the bearings is clearance and does not come in contact with the roll- Al'so, the center hole through which the screw enters? is clearance and this bore surface does not come in contact with the screw.

I claim:

1: Ina roller bearing nut, a housing, there being a plurality of equally spaced bores arranged in said housing, said housing being provided with a. longitudinally extending passageway for re-s ceiving alead-screw, a roller arranged each of said bores and provided with. means for engaging w-ith the threads on said lead screw; a plate arranged on each end of said housin said plates havin ltheir inner; surfaces cut away to define a. recessand a pad seated in each, of said recesses;

2. The apparatus. as described in claim I l, and further including securing elements" detac-ha-bly' connecting said plates-to the ends of said-hous ing, there being a port arranged in, said housing for the egress therethrongh-of a lubricant.

3. The apparatus as described in. claim 1;, wherein saidrollerbearing; nut is. adapted tube? used on a precisiontoolroomsuriace-grinder-or other machine tool, and-a pilot.- armextendingv from said housing to provide-a; guide t. A frictionless roller bearing nut. compris ing a housing, said'housing being provided with a plurality of spaced, parallel bores, a;-rollerrotatably arranged in each of said. bored and ex. tending longitudinally therethroug'h, there being a passageway extending lo ng-ituclinally through said-housmg and communicating with said bores,- sai'd passageway adapted to,- receive a screw therein, interengaging;- means on said rollers-and lead; screw, said housing being provided-witha; port for supp ying lubrican t0; the: interior of said housing, apilot guide member extending from said housing, a pair of plates mounted on;-

the'ends' of saidhou'sing, and. securing elements for detachablyconnecting said: plates to; said;

References. Cited in the, filGyOf this-patent UNI-TED swirl-E's PATENTS umber N me at 2.13. 1. Smi Sept. 27' 1938. 2,144,447 Barnhart Jan. 17,, 193 2....321A-s2. Wilson .a- -.-e- June 31. 9-5 2,525,326 Wahlmark oct. 10, 1950. 

